Chapter 5 – AT Commands, S-Registers, and Result Codes
SocketModem Global MT5634SMI Developer’s Guide 25
AT Commands
Command: AT Attention Code
Values: n/a
Description: The attention code precedes all command lines except A/, A: and escape sequences.
Command: ENTER Key
Values: n/a
Description: Press the ENTER (RETURN) key to execute most commands.
Command: AAnswer
Values: n/a
Description: Answer call before final ring.
Command: A/ Repeat Last Command
Values: n/a
Description: Repeat the last command string. Do not precede this command with AT. Do not press E
NTER
to execute.
Command: Bn Communication Standard Setting
Values: n = 0–3, 15, 16
Default: 0 and 15
Description: B0 Select ITU-T V.22 mode when modem is at 1200 bps.
B1 Select Bell 212A when modem is at 1200 bps.
B2 Deselect V.23 reverse channel (same as B3).
B3 Deselect V.23 reverse channel (same as B2).
B15 Select V.21 when the modem is at 300 bps.
B16 Select Bell 103J when the modem is at 300 bps.
Command: Ds Dial
Values: s = dial string (phone number and dial modifiers)
Default: none
Description: Dial telephone number s, where s may up to 40 characters long and include the 0–9, *, #, ,
B, C, and D characters, and the L, P, T, V, W, S, comma (,), semicolon (;), !, @, ^ and $ dial
string modifiers.
Dial string modifiers:
L Redial last number. (Must be placed immediately after ATD.)
P Pulse-dial following numbers in command.
T Tone-dial following numbers in command (default).
V Switch to speakerphone mode and dial the following number. Use ATH command to
hang up.
W Wait for a new dial tone before continuing to dial. (X2, X4, X5, X6, or X7 must be
selected.)
, Pause during dialing for time set in register S8.
; Return to command mode after dialing. (Place at end of dial string.)
! Hook flash. Causes the modem to go on-hook for one-half second, then off-hook
again.
@ Wait for quiet answer. Causes modem to wait for a ringback, then 5 seconds of
silence, before processing next part of command. If silence is not detected, the modem
returns a NO ANSWER code.
^ Disable data calling tone transmission.
$ Detect AT&T call card “bong” tone. The character should follow the phone number and
precede the user’s call card number: ATDT1028806127853500$123456789
Command: DS=y Dial Stored Telephone Number
Values: n = 0–2
Default: none
Description: Dial a number previously stored in directory number y by the &Zy=x command. Example:
ATDS=2